Rattlesnake, Southern Pacific

Scientific Name: Crotalus helleri

Fast Fact:

Most of the recent technological advances made in the field of night vision and heat vision is due to intense study of the Southern Pacific rattlesnake and its ability to locate its prey at night.

As this species ages, the venom grows stronger and more potent, able to kill larger animals that are needed to nourish a larger individual.

STATUS: This species is not listed on the IUCN Red List of Threatened Species.

HABITAT: The Southern Pacific rattlesnake makes its home in the deserts, fields, and mountainous hillsides of Southern California and northern Baja California. Incidentally, this rattlesnake is native to Griffith Park and the only rattlesnake species that occurs in the Los Angeles basin.

DIET: Because it is a nocturnal hunter, the Southern Pacific rattlesnake uses its flickering tongue to pick up scents of prey on the ground. The typical meal for this species (and most other rattlesnakes of the area) consists of small birds, mammals, and even other snakes.

PHYSICAL CHARACTERISTICS: The length of an adult Southern Pacific rattlesnake averages between 30 and 44 inches, making it one of the largest rattlesnakes found in California. Ranging from olive to more brownish-green in color, this snake blends in with the natural coastal vegetation that it typically inhabits. A thin dark stripe extends from the corner of each eye to the mouth. The back of this snake is usually a dark brown or black, with large spots of tan, grey, or even olive. As they get closer to the tail, the spots slowly turn into lines that follow the length of the snake and end at the rattle. The juveniles of this species can be distinguished by their bright, neon green tail that will eventually darken as the individual gets older.

Night Stalkers

These snakes are naturally adapted night hunters, and humans have studied these incredible snakes in order to better our own capabilities and advance modern scientific research. The Southern Pacific rattlesnake is nocturnal, meaning it hunts at night when light is very limited. To make up for this disadvantage, this snake has a tapetum (a tissue layer that shines when seen at night) that allows for more light to enter the eye and a very sensitive tongue that it uses to pick up the scent of nearby prey. Humans have studied this ability to hunt in the night to develop night vision goggles, which give humans the ability to see at times when we typically could not.

Another adaptation humans have learned by studying these snakes is heat sensitivity. Using receptive pits located between the eye and the nostril, all pit vipers (which include all rattlesnakes) are able to pick up infrared signals that help identify nearby animals that give off heat, helping them track prey or evade predators. Humans studied these heat sensing pits as well and consequently developed “heat seeking” capabilities which are able to identify the heat signature of living organisms.

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